Open seat (incumbent Republican Lynn Jenkins announced earlier this year that she would not run for reelection). The district includes the cities of Lawrence (Univ. of Kansas) and Topeka.
Insurgent Democrat: Paul Davis
Davis ran for Kansas governor against Sam Brownback in 2014 and made a credible showing, credible enough that some Democratic leaders wanted him to run again for governor in 2018. Instead, Davis has opted to run for this open seat. He's well known throughout Kansas and is getting the backing of the DCCC in Washington.
Interesting fact: Davis has already said that he will not vote for Nancy Pelosi as leader, and I agree with him on that. “This is a broken Congress right now, and I think the leaders of both political parties bear responsibility for that,” Davis said. “And I think that we need new leadership in both political parties.” God bless Nancy Pelosi. She's been Gal Gadot in the House, but it's time for new blood.
Virginia 10th Congressional District
Incumbent Republican Barbara Comstock, often mentioned as one of the most vulnerable Republicans in Congress. Cook Political Report rates this race a "toss-up." It's heavily suburban.
Insurgent Democrats: A whole tribe of them
Kimberly Adams -- educator
Julia Biggins -- scientist
Alison Friedman -- human trafficking activist and a former Obama staffer
Dave Hanson -- Naval intelligence officer
Dan Helmer -- veteran, has won the backing of the Democratic veterans group VoteVets
Julien Modica -- charitably described as a "perennial candidate"
Paul Pelletier -- 9th Democrat to get into the race. A former Federal prosecutor who directed high-profile public corruption investigations of lobbyist Jack Abramoff and
former congressmen Robert W. Ney and William Jefferson
Michael Pomerleano -- an immigrant from Romania with a Ph.D. from Harvard in business economics
Deep Sran -- school founder
Lindsey Davis Stover --communications strategist and a former Obama staffer
State Sen. Jennifer T. Wexton (D-Loudoun) -- already well known in the district and has the backing of most of the Democrats in the Virginia House of Delegates
California 39th Congressional District
Incumbent Republican Ed Royce, a committee chair and big target for a Democratic pick-up even though most prognosticators rate this district as leaning Republican. California peculiar primary system pits all the candidates together. Top two finishers face each other in November
Insurgent Democrats: Several
Gil Cisneros -- a Navy veteran and big lottery winner (no kidding!) who used his winnings to start college scholarships for Latino kids. He's self-funding his campaign
Sam Jammal -- former Obama Administration official and clean energy executiv
Andy Thorburn -- health insurance executive who loaned his campaign $2 million "to get started"
Mai Khanh Tran -- pediatrician who emigrated from Vietnam at the age of 9, has the backing of EMILY's List
Florida 26th Congressional District
Incumbent Republican Carlos Curbelo, a "moderate" who has separated himself from Trump and who polled less well than Hillary in this district in 2016. Rated a "toss-up" district.Insurgent Democrats:
Ricky Junquera -- young Democratic field organizer, motivated to run by Curbelo's vote to kill Obamacare
Steven Machat -- music producer who ran as an independent in last year's Senate race
Debbie Mucarsel-Powell -- front-runner, with EMILY's List backing. She ran a "stronger-than-expected" race in 2016 for a state senate seat and has impressed movers and shakers as a winner in 2018
Steve Smith -- founder of a tech consulting firm, describes himself as a "former liberal Republican"
Iowa 1st Congressional District
Incumbent Republican Rod Blum. Some prognosticators see this district as leaning R, but Cook rates it a toss-up.
Abby Finkenauer - A State House representative from Dubuque who announced her intention to challenge Blum way back in April. She's the 4th youngest member of the Iowa House
Thomas Heckroth -- comes from a well known Democratic family (his father was in the state senate) and was himself a staffer in the Obama administration
George Ramsey -- retired career military man
Courtney Rowe -- an aerospace engineer